3Com 3C16710 manual Bk MANAGING.FRM Page 34 Tuesday, October 7, 1997 1138 AM, Resilient Link Rules

16710.bk : MANAGING.FRM Page 34 Tuesday, October 7, 1997 11:38 AM

4-34 CHAPTER 4: MANAGING YOUR HUB USING QUICK CONFIG MANAGER

Resilient Links are available over twisted pair media (10BASE-T) because it carries a link test pulse which is used to decide whether the main link has failed and the standby link should take over. However, there is no such link signal over coaxial media (10BASE-2), so you cannot set up resilient links using the hub’s 10BASE-2 (Coax) port.

If you have more than two hubs there are a number of ways you can use resilience when linking them. Remember to follow hub connection requirements; always connect an MDIX port to an MDI port, setting the MDIX switch as appropriate, see “Connecting Hubs Using 10BASE-T” on page 2-10.

When your network is in use, the hub that has been used to set up the resilient link pair, monitors the state of both the main link and the standby link. If the main link fails, the standby link becomes active. If the fault with the main link is solved, the standby link stays active and the main link acts like a standby link.

You can use management to view the status of your links, and to send traps (messages) to an IP/IPX-based network management application, if anything changes.

Setting Up a Resilient Link Pair

To set up a resilient link pair, you need to manage the hub that both links in the pair are connected to. You can set up to 4 resilient link pairs for the hub.

When you set up your resilient link pair, you only need to specify the ports that the main link and standby link are connected to.

Resilient Link Rules

Always follow these rules when setting up a resilient link pair:

■Configure the resilient link pair at only one end of the link. In other words, only one hub controls each resilient link pair you set up.

■Each resilient link pair can only have one main link and one standby link.

■Each link must not belong to more than one resilient link pair.

■For a port that is part of a resilient link pair:

■Do not disable the link pulse generation.

■Do not enable security for the port.